diff --git a/src/AmoCRM.php b/src/AmoCRM.php
index d2b38fd..0a7dbe0 100644
--- a/src/AmoCRM.php
+++ b/src/AmoCRM.php
@@ -35,7 +35,7 @@ class AmoCRM extends AbstractProvider
      * @var array
      */
     public $headers = [
-        'User-Agent' => 'amoCRM/oAuth Client 1.0',
+        'User-Agent' => 'amoCRM/oAuth Client 1.1',
     ];
 
     /**
@@ -45,8 +45,10 @@ class AmoCRM extends AbstractProvider
      */
     public function __construct($options = [], $collaborators = [])
     {
+        $collaborators['optionProvider'] = new PostAuthOptionProvider();
         parent::__construct($options, $collaborators);
 
+
         if (isset($options['baseDomain'])) {
             $this->baseDomain = $options['baseDomain'];
         }
diff --git a/src/PostAuthOptionProvider.php b/src/PostAuthOptionProvider.php
new file mode 100644
index 0000000..1f1e6e2
--- /dev/null
+++ b/src/PostAuthOptionProvider.php
@@ -0,0 +1,26 @@
+<?php
+
+namespace AmoCRM\OAuth2\Client\Provider;
+
+use League\OAuth2\Client\OptionProvider\OptionProviderInterface;
+use League\OAuth2\Client\Provider\AbstractProvider;
+use League\OAuth2\Client\Tool\QueryBuilderTrait;
+
+class PostAuthOptionProvider implements OptionProviderInterface
+{
+    use QueryBuilderTrait;
+
+    /**
+     * @inheritdoc
+     */
+    public function getAccessTokenOptions($method, array $params)
+    {
+        $options = ['headers' => ['Content-Type' => 'application/json']];
+
+        if ($method === AbstractProvider::METHOD_POST) {
+            $options['body'] = json_encode($params, JSON_UNESCAPED_SLASHES);
+        }
+
+        return $options;
+    }
+}